Claims
- 1. A valve device which controls a valve disposed in a re-circulation passage connecting an air intake which supplies a gaseous mixture to an engine and an exhaust outlet which exhausts engine exhaust gas wherein said valve device comprises:an aperture regulation means which regulates an aperture of a valve by exciting a 2-phase motor driving said valve when receiving a valve drive command; and a switching means which switches an excitation mode of a motor from 2-phase to 1-phase when a fixed time period has elapsed after the completion of valve regulation by said aperture regulation means.
- 2. A valve control method comprising the step of controlling a valve disposed in a re-circulation passage connecting an air intake which supplies a gaseous mixture to an engine and an exhaust outlet which exhausts engine exhaust gas wherein said valve method comprises the further steps of:regulating an aperture of a valve by exciting a 2-phase motor driving said valve when receiving a valve drive command; and switching an excitation mode of a motor from 2-phase to 1-phase when a fixed time period has elapsed after the completion of valve regulation by said aperture regulation means.
- 3. A valve control method according to claim 2, wherein a motor driving condition is set in response to a deviation of a current valve aperture and a subsequent target value.
- 4. A valve control method according to claim 2, wherein after driving the motor is terminated, a reverse rotation pulse is given to the motor for the extremely short period of time in which the motor can not respond.
- 5. A valve control method according to claim 2, wherein when a valve aperture is regulated, the excitation mode of said motor is switched from 2-phase to 1-phase when on comparison of the motor load with a reference load, the load on the motor is smaller than a reference load.
- 6. A valve control method according to claim 2, wherein when a valve aperture is regulated, said motor is driven at a 1-2 phase excitation when the motor is operated variably and is driven at a 2-phase excitation when the motor is driven at a fixed rotation speed.
- 7. A valve control method according to claim 2, wherein a non-responsive region is provided in the variation of said target value and when a deviation of a current target value and a subsequent target value is within said non-responsive region, said motor is not rotated only when the direction of the previous rotation and the subsequent rotation differ.
- 8. A valve control method according to claim 2, wherein a rotation speed of said motor is reduced when a valve aperture is smaller than a reference aperture in comparison to when it is larger than said reference aperture.
- 9. A valve control method according to claim 2, wherein when said valve is totally closed, the rotational speed of said motor is increased in comparison with when said valve is stopped midway.
- 10. A valve control method according to claim 2, wherein an initializing operation of said valve aperture is performed during cranking said engine.
CROSS-REFERENCE TO THE RELATED APPLICATION
This Application is a continuation of International Application No. PCT/JP98/05971, whose International filing date is Dec. 25, 1998, the disclosures of which Application are incorporated by reference herein.
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Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/JP98/05971 |
Dec 1998 |
US |
Child |
09/642663 |
|
US |